rumen fluke diseASE now a major animal health threat
Spotting and dealing with the condition is tricky for herd owners and vets writes Mícheál Casey
The rumen fluke (scientific name Paramphistomum cervi) was little known outside parasitology circles until recent years. It used to be considered harmless, and small numbers of these short pink maggot-like parasites are commonly observed in the first stomach (rumen) of healthy cattle and sheep at slaughter.
Much heavier burdens of adult rumen flukes have been observed in cattle and sheep from some Irish farms in recent years by the regional veterinary laboratories. This phenomenon has also been reported from Northern Ireland and south-western Britain.
Although adult flukes seem relatively harmless, a small number of outbreaks of severe rumen fluke disease have been seen on farms in the north-west, the south and the midlands, caused by very heavy burdens of immature (larval) flukes. This stage of the parasite feeds on the lining of the upper part of the small intestine (the duodenum) and causes very severe enteritis and diarrhoea if large numbers of larvae are present.
What are the signs that rumen fluke may be in your herd?
The clinical disease is rare, but tends to be very severe when it occurs. Affected animals are dull, dehydrated, and lose weight rapidly. They develop a profuse and severe watery scour, which may contain traces of blood. Affected animals may become anaemic, and if blood protein levels drop sufficiently, may develop a swelling under the jaw -- known as bottle-jaw.
How do I confirm that rumen fluke is causing these signs?
Confirming milder cases is not easy -- other parasites may cause similar signs. Your vet can advise on whether rumen fluke may be involved, and may take samples for testing.
Laboratory testing may detect rumen fluke eggs. But this merely proves that the animal is carrying adult rumen flukes (not uncommon). It is much more difficult to confirm disease caused by immature flukes, as there are no conclusive findings in faecal or blood samples. Your vet will interpret the results in light of the clinical signs shown by the animals.